Drilling deep holes in wood



Feb. 6, 1940. J. W.STOILLE 2,188,929

DRILLING DEEP HOLES IN WOOD Filed June 20, 1936 4 Sheets-Sheet 1INVENTOR John W. Stolle BYn Feb. 6, 1940. J. w. STOLLE DRILLING DEEPHOLES IN WOOD 4 Sheets-Sheet 2 Filed June 20, 1936 Feb. 6, 1940.

Filed June 20, 1936 4 Sheets-Sheet 3 Troy/1 Feb. 6, 1940. J. w, ST LLEDRILLING DEEP HOLES IN WOOD Filed June 20, 1956 4 Sheets-Sheet 4INVENTOR John W Sta! [6 BY 9 I ATTQRKJEY Patented Feb. 6, 1940 PATENTOFFICE DRILLING DEEP HOLES IN WOOD John William Stolle, Danbury, C'onn.,assignor to Charles W. Stevens, Danbury, Conn.

Application June 20, 193 Serial No. 86,244

7 Claims This invention relates to the woodworking art, and particularlyto the formation of holes in textile spools and bobbin blanks and thelike, and

A particularly to the drilling of straight deep holes having sections ofdifferent diameter in elongated blanks by the use of relatively slenderand flexible drills.

In the drilling of these blanks according to conventional practice thereis a very substantial 10 Waste and loss of material due, among otherthings, to the long slender drill or boring tool being deflected fromits rectilinear path by the grain of the wood which is not alwaysparallel to the hole to be driven. This difficulty may be largelyobviated by the use of the invention of my Patent No. 1,513,350, issuedOctober 28, 1924, which comprises the use of a drill having a specialcutting and shaving edge and a stream of liquid, such as water or oil,to wash out the chips which are formed during the drilling operation,and to moisten and soften the wood to be bored. While the liquid step issatisfactory in some branches of the wood boring art, such as the boringof hook handles, whifiletrees, wood machine rolls,

etc., I have found that in the drilling of textile spools and bobbinblanks that the oil or soap water employed has a deleterious effect uponthe Wood.

One object of the invention,therefore, is the provision of means forutilizing compressed air andthe like to blow out the chips and cuttingsduring the boring operation, together with the provision of a specialdrill which, in addition to the patented features of my Patent1,513,350, embodies features particularly adapted to the use ofcompressed air and capable of forming a,

hole in a manner which is self directing and guiding along a straightrectilinear path, notwithstanding the non-parallelism of the Woodgrains.

40 A further object of the invention is the formation of a holehavingseotions of different diameter through a wooden blank, as forexample a blank having an elongated hole of three differentcross-sections, by first, and in one operation, drilling a hole equal tothe desired diameter of the middle section of the blank and then inanother single operation continuing the hole at a smaller diameterthrough to the end and reaming out the other end and by the use of adrill which does not rub against the walls of the intermediate holepreviously formed.

A further object of the invention is a drill of the above indicatedcharacter which leaves an uncut core of wood in the center of the blanksurrounded "by a cylindrical guiding groove for assuring the straightrectilinear progress of the drill through the blank, notwithstanding thefibrous character of the wood. I

A further object of the invention isa novel and I, improved form ofmachine for drilling and bor- 5'. ing wooden blanks of the aboveindicated character.

For a better understanding of the invention, reference may be had to theaccompanying drawh ings forming a part of this application wherein: 10

Figs. 1 to 5' inclusive are .diagrammaticviews illustrating steps in thedrilling of a blank ac cording to the invention; V

Fig. 3a is an enlarged sectional view showing the cylindricalcentralguiding core and the sur- 15 rounding cylindrical guiding grooveformed at the bottom of the, bore. U

Fig. 6 is a plan view substantially enlarged of the end of the drill; f

Fig. 7 is an end view thereof; 1 20 Fig. 8 is a side view of themachine;

Fig. 9 is a plan View of the machine;

Fig. 10 is a side view showing a step in th operation of the machine;

Fig. 11 is a sectional viewalong the line il ll 25 n of Fig. 8-; and iFig. 12 is a detail view of certain parts of the machine.

Referring to Figs. 1,to 5, I have indicated at l a textile bobbin blankor the like to be drilled 30 and at 2 a drill according to thevpresentinvention for drilling and forming a hole 3 of the desired diameter inthe middle section of the blank.- This drill 2 forms the bore 3 to thepoint 3-where it is desired to discontinue the bore of that sec- 35tion.

At 4 I have shown a drill which continues the bore throughout the blankto form a bored section 5 at one end and simultaneouslytherewith to reamout a section 6 of a still larger bore at 40 the other end; thecompleted drilling operation being indicated in the blank of Fig. 5. Themultiple section bore 3, 5 and 6 of the'blank is formed in twooperations; the drill 2 forming the bore indicated in Figs. 2 and 3 andthe drill 4 forming the bore} and 6 of Fig. 5. Fig. 4 shows the seconddrilling operation. The shank I of the drill- 4 is of smaller diameterthan the intermediate bore 3 of'the'blank. r

I have found that by drilling the hole inthe ,0 I

two operations by thetwo drills 2 and 4,that the a tendency of the drillto be deflected from a reeftilinear path during the relativelongitudinal and rotational movements of the blank and the drill issubstantially reduced. I believe this due to reduction in vibrations ofthe long slender drill which are present when a single drill is utilizedfor drilling simultaneously both larger and smaller bore sections,namely, when the drill is engaging the wood at two or more Widelyseparated points longitudinally of the blank. According to one aspect ofthe invention the drill 2 is utilized for forming the intermediate bore3, While the drill 4 is utilized for forming the end bores 5 and 6. Thereaming part 8 of the drill 4 for forming the enlarged bore end 6 doesnot come into operation until the bore 5 is on its way to coinpletionand, accordingly, the drilling operation of the two ends of the blank atthis stage does not produce the same tendency to deflection as when thetwo operations occur at points closer to the middle section. By havingthe shank Iv of a smaller diameter than the bore 3 the rubbing of theshank against the walls of the 'bore'3 is prevented, thus removing anydanger of vibration from the tip 9 of the drill, while it completes thebore 5.

For disposing of the chips and cuttings as the drill progresses, Isupply fluid gaseous pressure, such as air, through the passages I0,Ifl' formed longitudinally of the drills. This passage or channel I0(18') passes down through the tip 9 of the drill and the compressed airor other gaseous fluid blows the chips and cuttings backwardly along thedrill, namely, along the groove II which is formed in the side of thedrill.

' As afurther means forobviating deflection of the long slender drillfrom a straight rectilinear path, notwithstanding the departure fromparallelism of the Wood grain, I have provided a drill tip 9 formedgenerally as indicated in Figsrl to 4, and as morespecifically'illustrated in Figs. 6 and '7. This improvement consists offorming theltip '9 of the drill so that it will' form in advance of thebores 3 and 5 an annular groove I5 which approaches the cylindrical formwith an uncut core I6 surrounded by the annular groove l5 and disposedin the axes of the bores. For this purpose 'I have provided the, tip 9of the drill with a relatively short pilot cutting section I! eccentricto or'oflfset from the axis I 8 of the drill and bores. This pilotsection I'll is of lesser diameter than: the main body tip 9 and formsthe groove i5 and the core I6 in advance of and in alinement with thebores 3 and 5. The pilot section is formed on, the advancing edge II {ofthe drill, that is, relatively'to the blank I and it may be milled orground at I9 to form the cutting edge 20. The drill is provided with acutting and reaming side edge 2| (preferably formed by milling orgrinding, as indicated at H) of my patent above referred to. Thus, tworeaming edges 20, 2| and three'boringedges ll, I1 and 22 are provided,the edges I1, ll of the pilot section forming a salient. The groove IIin the side of the drill should be deep enough to accommodate the uncutcore I 6 which isformed on the axis I8 of the blank and drill. Thismaybe effected by having the, sides of the groove II meet at a point farenough beyond the axis I8 to clear the core being formed; or, as isshown in Figs. 6 and 7, the drill may be provided with a centralcircular groove 25 to accommodate the core with the sides of thelongitudinal groove ll discontinued at the groove.

.The dimensions of the groove I5 and the uncut core I6 may be varied tosuit particular requirements, but generally the core should be ofsulficient diameter and stifiness correlated with the depth of thegroove I5 to aid in keeping the drill concentric with the'axis of therelatively rotating 2,188,929 I e I drill and wooden blank. I'have foundin prac tice that a core one-fourth the diameter of the bore, namely,with the core I6 one-fourth the diameter of the bore 3, is efiective,with the depth of groove indicated in the drawings in guiding andcausing the drill tip 9 to follow a straightrectilinear path,notwithstanding the direction of the Wooden fibres and the slendernessand flex'i-y' bility of the drills. The uncut core I6 is illus-"trated'as of compartively short but substantial depth.

The drill itself is of very small diameter and in operation the outerfree end of the core is. 1

gradually and progressively broken or twisted off,

due to its small diameter.

In Figs. 8 to 11 I have shown somewhat diagrammatically a machine fordrilling and boring, blanks in accordance with my invention, thismachine embodying novel and improved mecha-I nisms'for drilling deep,straight holes in Wooden blanks for formingtextile spools and bobbinsand the like. The machine comprises a bed plate 30,

having mounted thereon at one end ahead stock flexible pipe or hos'eAElleading through suitable fittings M to passages formed in the chucks orsockets 36, 31 which receive the drills,,the air pressure being suppliedto the passages II! of the drills. The'carriage 35 is reciprocated alongthe guideway 33 by means of a mechanism including a pivot le'ver'44pivoted to the'bed at 44', the carriage and the lev'erbeingoperativelycon.- nected together by a link 45 which is pivot-ally attached at 46 tothe carriage and to the lever at v 41. The lever 44 is provided with anumber of openings 48 to provide for the adjustable attachment of theend 4'! of the'link 45 to the pivoted lever 44. The lever '44 isoscillated about the pivot point .44 by means of a crank shaft 49.suit,-

ably journaled in the tail stock 32 and having a crank 50 whichoperatively engages thelever 44. The driving connection between thecrank 52] and the oscillating lever 44 consists of a sliding bearingblock 5I which'is pivotally fastened to' the crank 50 and this block 5iis guided by and slides back and forth in an elongated slot 52 formedlongitudinally of the lever 44. The pivot point 44' of the lever isbelow the axis of the shaft 49, and at the position of the drillcarriage indicated in Fig. 8, namely, at the end of the return stroke ofthe drills, the pivoted lever 44 is to the left of the axis of the shank49 and the bearing block 5I is disposed about midway the ends of theslot 52. Therefore, with the shaft 49 turning clockwise (Fig. 8) arelatively slow forward movement of the drill carriage 3515 pro-;

duced and a relatively fast return movement is obtained, because in theformer the-operative connection between the crank and the lever 44nearer the outer end of the slot; 52 and-in the latter it is nearer theinner end thereof. 6 The drive for the shaft 49 is diagrammaticallyillusnism 54 and a drive shaft 55. l

705 trated, comprising the gear reduction meehaf Inthe particularembodiment shown therelas v tive longitudinal movement between-thedrills and the blanks is produced by moving "the drills 2,188,929longitudinally by means of the reciprocating drill cluding the axis ofthe drill. For this purpose the head stock 3| is provided with a pair ofspindles 6I and 62 which are driven in anysuitable man ner,;as forexample by the belting indicated, and which are suitably journaled inthe head stock 3|, these spindles carrying at their inner ends adjacentthe magazine 60 gripping chucks 6| and 62. The chucks 6| and 62' are inline with the drills 2 and 4 and the arrangement is such that when theblanks disposed in the magazine 60 are pressed against these chucks theblanks are caused to rotate at a high speed. The chucks BI and 62' areprovided with recesses 64 and teeth 65 which function to bite into theend of v the wooden blank to be bored when the blanks are pressedthereagainst. The blanks are brought into driving relation with thechucks 6| and 62' by means of a pair of reciprocating work support units66 and 61 which are reciprocated back and forth along the guide rods 33and 34, each work support being mounted on an outer rod 33 and theadjacent rod 34. Each of these work supports. is provided with a bearing66 and 61' in alinement with the drills and the'chucks BI and 62. In

these bearings are disposed guide bushings or sleeves 68 through whichpass the drills to and fro-in their reciprocating'movements. On the endof each sleeve 68 there is journaled a chuck 69 having a conical recess10. These journaled chucks 69 engage the blanks I when the work supportsare moved forwardly to press the blanks against the driving chucks 6|and 62'.

i The work supports 66 and 61 are independently biased in a direction toengage the blanks. and force them against the driving'chucks. In theparticular embodiment shown, this biasing operation is obtained by meansof Weights I2 fastened by chains 13 fastened over pulleys I4 andattached to the work supports. The chucks of the work supports areautomatically withdrawn from engagement with the blanks against theweights 12 by means of pull rods 15, which are fastened at one end tothe drill carriage 35 and at the other end pass through openings formedin the work support uprights l6; and these pull rods 15 are providedwith heads 15 which engage the uprights 16, when the drill carriage 35nears its outermost position, to withdraw the work supports'and theirchucks from engagement with the" blanks. i .1

The magazine 60 consists of an intermittently rotatable frame journaledupon a shaft 80, the latter being carried in any suitable manner, as forexample by the head stock 3|, and this shaft 88 isin the horizontalplane of the drillsand the chucks; The magazine frame consists of asleeve journaled upon the shaft 89 and carrying end discs lilv and 82.These discs carry near their peripheries eight cylindrical receivers.83, these cylindrical receivers and carriers being intermittentlyalineable with the chucks and being shorter than the blanks in orderthat the chucks may engage the projecting ends of the blanks forrotating them. This magazine 60 is intermittently rotated one-eighth ofa revolution at each complete reciprocation of the drill carriage 35.

tively in engagement with the ratchet teeth 85,'

there being altogether eight ratchet teeth and this pawl 86 moving themagazine 60 through oneeighth of a revolution at each reciprocation.

The pawl 86 is carried by one arm 81 of a bellcrank lever pivoted at89-upona bracket 90 carried by the machine bed. The other end 88 of thebell-crank lever is engaged and operated by an upright 16 which carriesa finger 9| for that purpose, the finger 9l engaging the outer end ofthe lever 88 when the work support is actuated to the left (Fig. 8),which causes the upward movement of the pawl 86 and the movement of themagazine through one-eighth of a revolution. Upon movement of theworksupport to the right the bellcrank lever 81, 88 operates by gravity tocause the pawl 86 to engage the next lower tooth for the nextintermittent operation. Any suitable means may be provided forpreventing the overtravel of the magazine 60, namely, beyond. thepositionto which it is actuated by the pawl 86. For this purpose I haveshown a belt or rope friction means 93 disposed in agroove on the hub 8i of I the end plate 8|, one end of this belt or rope being attached tothe frame and the other end having a suitable weight. attached thereto;This operates as a friction brake to prevent overtravel of the magazine.

A hopper95 is shown for containing the charge of blanks I for drilling,the lower part of this hopper consisting of a receptacle 96 which holdsa blank in alinement with the uppermost cylindrical receiver 83 of themagazine 60. The lowermost blank in the hopper .95 is automatically fedto the uppermostreceiver 83 by means of a push rod 91 mounted inalinement with the receptacle 96 and the receptacle 83 and adjustablycarried-at one end by a bracket 98 carriedfrom the drill carriage 35.The receptacle 96 being open at both ends the push rod 91 in eachforward movement of the drill carriage 35 pushes the lowermost blank outof-the receptacle 96 and into the uppermost receptacle 83' of themagazine. The blank which is being pushedinto the cylindrical receptacle83 automatically pushes out a drilled blank therein onto a trough I00.Cam or lining members llll are mounted adjacent one end of the peripheryof the magazine to engage the blanks disposed in the cylindricalcarriers 83' to adjust the blanks automatically to a position whereintheir ends will not foul the chucks.

I As indicated above, eachdrill is supported by a butt or socket 4| towhich the compressed air fitting 4| is attached, the set-screws 38permitting the removal and replacement of drills. I prefer to make thedrill tip 9 separate from the shank to avoid the necessity of drillingthe relatively small air hole ID the entire length of the drill. a Thetip may be brazed or welded to the shank. When the overall 'length ofthe shank carriage 35 the push rod 91 pushes a blank from the hopper 95into the uppermost cylindrical receptacle 83. At the first backwardmovement of the drill carriage 35 the magazine 69 is rotated one-eighthof a revolution and on the next forward stroke another blank is fed intothe magadoes not exceed [2 inches I prefer to make the forward movementof the drill carriage 35 'results both in the supply of another blank tothe intermittently'rotated magazine 68 and on for- Ward movement of thedrill 2 to drill the middle section bore :3. Before the drillreaches theblank 1:9 the pull rod l5'which is carried by the drill carriage .35releases the work supports 66 which then moves forward under theinfiuence' of the weights #2 to engage and line up the blanks disposedin the receptacles 83 in line therewith. The forward movement of thework support 66 also presses the blank against its corresponding drivingchuck 6!, 62, whereupon the blank is rotated at .a rapid speed while thedrill 2 advances to form the bore. .At'each reciprocation thereafter ofthe drill carriage '35 a blank'is supplied tothe magazine 60, the bore'3 is formed in a blankand the magazine fit is advanced one-eighth of arevolution. When the blank formed with the bore .3 reaches thethree-fourths position the drill 4 comes into operationto form the bores5 and 6.

This operation continues as long as the hopper 95 and the magazine 60contain blanks to be drilled.

The flexing of; the long slender drills is pre- 38 vented according tothe method of drilling above set forth. 'In the first drillingoperation, which is performed by the drill .2, only the bore part 3 isformed, namely, a bore of one cross section throughout and the'boring iseffected only at 'one point throughout the length of the drill, namely,at the tip 9.' Accordingly, the flexing of common practice, which Ibelieve to be due in part to drilling two .or more different sectionssimultaneously, is thereby prevented or minimized. Moreover, by formingthe annular groove I5 slightly in advance of the bore 3 and the uncutcore l5 and groove form a guide and directing means for the drill tiptending to keep it in a 7 straight rectilinear line, namely; along theaxis of the blank and'notwithstanding the particular fibrous characterof the wood being worked upon.

When the drill 4 isxintroduced into the bore 3 to form the smallersection bore 5, the guiding groove l5 and the uncut core I6 function toaline and center this drill not only at the beginning of the operationbut throughout the formation of the bore 5'. The. compressed air supplythrough the flexible pipes .45 continuously blows out the chipsandcuttings and clears the end of the bore for fresh cutting operations.

I claim:

1. The method of drilling holes of relatively small diameter throughelongated wooden blanks which consists informing a bore of the desireddiameter therein with no'uncut core portion extending therethrough andsimultaneously with the formation of thebore forming an annularcylindrical-like groove a short uncutcor-e I in the center thereof inadvance of the bore throughout the drilling operation-for 'guiding thef;

drill in the rectilineardireotioni I 2. The method of forming a borehaving sec-- tionsof different'diam'eters inelongated wooden blankswhich consists in drilling onebore section part Way through the blankand form-ing 'a cen f 1 tral guiding core at the bottom thereof in-oneQsingle operation and continuing the bore into -a bore of smallerdiameter by means of a drill whose shank and'tip are ofsmallerdiameter", than that-of the first bored sectionwith said core guidingand positioning the drill of smaller di v ameter. l l

3. The method of forming a bore having sec.

7 tions of different diameters in elongated wooden blanks which consistsin drilling one bore section a part way through the blank in one singleoperaer diameter by means of a drill whose shank and I tip are ofsmaller diameter than that of the first bored section and simultaneouslyreamingo'ut'.

the end of the first bore formed to form a 'bore of larger cross sectionthan either of theother bores.

"4.. The method as set forth in claim 3 comprising thestep of forming atthe bottom of the first bore section part a centrally disposed coreandannular groove for guiding the second drill.

5. The method of drilling holes .of relatively small diameter throughelongated wooden blanks which consists in forming a bore of the 'desireddiameter therein with no uncut core portion extendingtherethrough andsimultaneously with the formation of the-bore, reaming the [side thereofand forming and-maintaining in advance of the'bore throughout thedrilling operation a centralguiding core of short but substam tialdepth-extending into the chip channel for. guiding the drill in therectilinear direction. v

6. ,The method of drilling holes of relatively small diameter throughelongated woodenblanks which consists'in forming a bore of the desireddiameter therein with no uncut core portion exe tending therethrough andsimultaneously with throughoutthe drilling operation for guiding thedrill in the rectilinearldirection. v

7; The method of forming a bore having sectionsof differentdiameters inelongated wooden blanks which consists in drilling one bore section partway through the blank and forming at the bottom thereof a centrallydisposed core and. :an-

nulargroove therearoundand continuing the bore into a bore .of smallerdiameter by means of a drill whose :tip .isof smaller diameter than thatof the 'firsthbore section with said coreguiding and positioning thedrill of smaller diameter.

' j JOI-IN'W. STOLLE.

tion and continuing the bore into a bore of small- 3

